Continuity mistake: When the chopper carrying the soldier with the wounded back takes off, the sky is cloudy and, even accounting for the poor quality of the film, the weather looks very dull. The shot changes to show Radar, Hawkeye and Margaret watching the chopper leave and it is now bright sunshine. (00:44:20)
Continuity mistake: After Radar calls assembly, Potter starts to address the personnel. Accounting for Hawkeye, BJ, and Margaret in Surgery, there are only thirty-three people there. In the episode "Dear Ma" (S4: Ep 17), Radar wrote that there were almost two hundred people there.
Character mistake: At the end of the episode, while Col. Potter is in the helicopter asking where they are, the pilot says they are about 10 miles west of Inchon. Col. Potter says this is no good and he tells the chopper pilot to "head west, towards Inchon." If they are already west of Inchon, heading west will take them further from Inchon.
Continuity mistake: After a distant aerial shot of Potter's chopper, the camera closes in for a close up. When in the distance, the rotors are running full speed. In the close up, they are barely running, just enough to make the familiar whooshing sound. The chopper that they are in is being raised and lowered to simulate flight. Also, if you look in the canopy in front of Potter, you can see the camera and crew's reflection. Then when the chopper is over the building, the sound of the blades is still the slow moving whooshing mentioned earlier, instead of the full power sound it should be.
Revealing mistake: When Radar salutes Major Burns dropping the package, you can see wet spots on his uniform where he held the package. Before the bottle inside breaks, it is supposed to be dry. The crew probably re-used a single package for several takes of the shot. (00:04:45)
Other mistake: As Frank cocks his gun in the Swamp, the slide locks open and he has to hit the slide release to get it to move forward. Next he fiddles with the hammer. Next we hear the shot go off. Burns' excuse later is that he was cleaning The Gun and it went off (although admittedly, Frank doesn't always stick to the truth that religiously in situations like that). The slide on a semi-automatic locks open only if the magazine is empty or missing. The Gun locking open is also a clear, unmistakable indication that the breech is empty. He would have to insert a filled mag, then pull the slide back again to chamber a round before The Gun even had the chance to go off. One never does that while cleaning a gun. One does what Frank did to begin with: Pull the slide back without a magazine inserted to make sure the breech is empty.
Factual error: Klinger says he would wear Hula Hoops(R) in his ears if it would get him a discharge. For several reasons, he is using a phrase that does not yet exist: 1) Show wise, Klinger will later try to convince Charles to invest in developing a new toy, a hoola hoop like plastic tube, being inspired by Korean children playing, and 2) plastic hoops which came to be called Hula Hoops were only introduced by Whamo in 1958. Setting episode dates is always difficult for MASH, but the Mash Olympics (inspired by the 52 Helsinki games) are still to come so we can say it must be 52. 3) The Hula Hoop trademark was only registered in 1962 to Whamo. No info. as to what name the hoops were marketed under prior to 62, but Klinger is using a term at probably ten years, at least 6 years, before it came into use. (00:04:00)